Such a rail guide is known from DE 42 38 486 A1, for example FIG. 2 of DE 42 38 486 A1. Other rail guides are known from U.S. Pat. No. 5,941,495 A and DE 10 2006 048 786 A1. Additionally, reference is made to DE 10 2006 047 525 A1.
The two rails of a pair of rails in the rail guides according to the prior art extend in a straight line. This has great advantages; the rails can be manufactured and, if necessary, aligned with precision, attachments are simple and a consistently good adjustability over the entire length of the adjustment distance can be obtained.
In the case of straight rails, there is, however, the disadvantage that the seat is only moved in a linear manner in space when adjusted, but that no other movements are possible. However, it was now found out that a tall passenger, who sets the seat far towards the rear and low in a downward direction, generally also inclines the backrest more towards the rear relative to the vertical than a smaller passenger, who will set his seat more towards the front and higher. According to the prior art, the inclination of the backrest can only be adjusted by means of a separate backrest joint. However, if such a joint is provided, this means a certain expenditure. The inclination of the seat surface is also chosen differently by tall and small persons. In order to be able to adjust the inclination of seat surface, there are seat inclination adjustment mechanisms. They offer good comfort but also require added expenditure. A height adjustment mechanism with which the height of the seat surface can be adjusted is also frequently provided. In principle, these and any other additional adjustment device mean added weight and expenditure as regards material and assembly.